Xerosis and Scaling in Neonates and Infants
The epidermal barrier is composed of corneocytes, held together with corneodesmosomes.26,27 SC barrier function depends on the complex interplay among SC pH, desquamation rate, and the appropriate ratio of skin lipids.16 The intercellular lamellar lipid membrane is primarily composed of CERs, cholesterol, and fatty acids, which play a vital role in SC hydration’s physiological maintenance.28,29 The SC lipids are composed of CERs (40–50%), cholesterols (20–33%), and free fatty acids (7–13%).28,29 Other SC lipids include cholesterol-3-sulfate (0–7 %) and cholesteryl esters (0–20 %).28,29 The SC contains numerous different CERs. The number of hydroxyl groups in the head group of the CERs appears to be playing a critical role in the SC barrier function.28,29
The importance of the individual structural features of CERs is not fully understood.16,29,30 In neonatal and infant skin, the ratio of free fatty acids/cholesterol/CERs is not static.14 Without the proper CERs ratio, the SC barrier function can become incompetent impairing barrier homeostasis, leading to dryness, irritation, erythema, and itching.16
Premature infants SC is deficient in essential fatty acids due to less fat-storing capacity.21,31 SC lipid deficiency can present as superficial scaling of the skin and desquamation and irritation in the neck, groin, and perianal areas.21,31
Xerosis in infants may be indicative of a predisposition to AD. An impaired skin barrier function (measured as increased TEWL) assessed at birth and two months of age may precede clinical AD.25,32
The panel members agreed that prevention of AD is a broad topic that requires discussion of key studies and evidence beyond this algorithm’s scope, which focuses on skin barrier function and the role of skincare in healthy neonates and infants.
Skincare
Skincare, including a gentle cleanser and moisturizer, is important in all neonates and infants and should begin immediately after birth, but must be safe and products must be appropriate for a newborn’s skin based on its unique characteristics (Box 1).
Newborns and infants have a high surface-to-weight ratio, immature epidermis, and a compromised skin barrier, making them particularly vulnerable to transcutaneous toxin exposure.12 Topical agents, which are harmless for adults, may cause respiratory distress, neurological toxicity, and even death in infants depending upon systemic absorption.12 Topical agents that may cause toxic reactions include isopropanol, benzocaine, pyrethrin, hexachlorophene, and salicylic acid, among others.12
Skincare for neonates and infants should be safe, effective, fragrance and sensitizing agent-free. Skincare with CERs may benefit the stratum corneum’s lipid and water content.14
Skin Hygiene and Cleansers
Bathing details are provided in Box 2. The frequency of bathing and time of day should be based on individual preference.14
Soaps, surfactants, and detergents, especially those with an alkaline pH, may excessively remove skin lipids, which is explicitly damaging to neonatal and infant skin.14 Skin cleansers with a near physiologic skin surface pH (4.0–6.0) containing CERs and no soap are less irritating than alkaline soaps and may reduce skin irritation (Table 4).9,14,15,21-23 When the skin is dried, corneocytes’ rapid dehydration can lead to their release from the lipid matrix, creating cracks and facilitating penetration of
